— A vehicle’s horn must not be unreasonably loud or harsh, nor can it be a whistle. I have heard some of these horns -- thankfully, infrequently. They can be very startling and, therefore, dangerous and distracting.
As motorists, we are all required to have horns in our vehicles. Each horn must be audible, under normal circumstances, from a distance of no less than 200 feet. We are to use our horn as a warning to insure safe operation and if a warning is not necessary, they should remain silent. Vehicles cannot be equipped with a siren, whistle, or bell unless authorized by statute -- this primarily would refer to emergency vehicles.
I recommend calling your local law enforcement agency to look into the situation if this is local and/or frequent in your community or neighborhood. Many times, such enthusiasts are not aware of the problems or the law.